I use auto text on my blackberry to decide where to file the task for easy things like @Home @Office @Phone and a general inbox for things I want to get off of my mind.

2. Repeating Tasks with repeat on completion - Very useful for setting up reminders that may or may not need to be done on a specific date. It automates the next occurrence automatically based on the date of completion.

3. Due Date view - My default view that keeps me focused on the day at hand. Sorted by Context then by Importance.

4. Add multiple tasks - Great for brain dumps. Get everything off of your mind so that you can focus on what is most important at the time. Even work on the Blackberry Browser while I'm on the road.

5. Statistics Page - I'm a numbers guy and i like to see how I'm doing. The statistics page helps keep me motivated and track my peak productivity days.

Only five?!
Okay, I'm going to try to do this off the top of my head...

5) Goals. I have a bunch of vague goals that serve only to remind me how *I* will benefit from doing each task. Some tasks have only the purpose of practicing being punctual or overcoming procrastination, and I find that worth reminding myself.

4) Hotlist, sorted by Importance. It takes "What to do next?" out of my head, and into my face. Gotta love that!

3) Ubiquitous capture, and fast! Here's how I do it:

- I have the Toodledo add-on (Firefox 2 edition) set up to allow me to put just the task name, due date and time, and priority. This gives me enough control that the task will appear on my Hotlist if it really should be there, but doesn't bog me down with pinning down details like folder or context.

- I use either Jott or twitter when I'm away from the computer, depending on how loud the surrounding area is, or whether I really need to ensure the task gets a due date or priority set (twitter can, Jott can't).

- If I find myself scribbling a bunch of to-dos on paper, I can use the multi-add feature when I next sit down at the computer.

- For all of the above: if a task has no Folder, it's considered to be in the "Inbox", which is processed regularly to zero.

2) Flexible views. In particular, I LOVE the multi-line view, especially because of how the Sort parameter is the only one listed next to the tasks when in "Hide Details" mode. This keeps me focused on just the thing I'm thinking about, and also makes it easier to change that parameter for a bunch of tasks, quickly. (I don't actually use the sub-sorts often at all, as it slows down my switching between sorts.) I'm gonna count the Star as part of this flexibility, because it is really something I use ALL the time, to keep myself focused on what things I've chosen for myself TODAY.

1) The developers, their awesome interactivity with us, their rate of development, their choices of what to implement and when to release it to us... you folks totally rock. I mean, really. (And yes, Jim, I think this is a feature. :P)

1.Number one: (the reason I am keeping my iPhone 3G)
The Toodledo Iphone interface is incredible. Better than the web interface for quick ins and dones.
2. Jott - I love Jott for everthing and now killer iphone interface
3. Stars, folders and Tags, this makes my life so much easier when trying to figure out what to do.
4. Email Task - Have been doing this for years and I love it.
5.Incredible flexibility of views.

Thanks so much for this great app which I am revisiting after purchase of my iPhone. I like the function of my Treos, and was contemplating returning my beautiful but stupid iphone, and then saw the Toodledo interface, I am keeping the iPhone. I am the biggest procrastinator, time waster in the world, and Toodledo helps me a great deal. Thanks!

1) SMS alerts (w/AT&T's SMS Alias system: http://mymessages.wireless.att.com )
I stopped using email push, due to the battery hit. The SMS alerts truly get my attention, so I love 'em. I especially appreciate the way the alerts can be tied into the priority scheme.

2) iPhone friendliness combined with status vs context vs folders

3) ability to really finetune "repeats", i.e., every 4 days from date of completion

4) astonishing ease with which you can flip back and forth among assorted views

5) price structure-- I was actually happy to pay the annual fee for "Pro", which gives me sub-tasks -- a great way to handle project-style multi-step tasks, whether via browser or the iPhone